Java常见笔试、面试题目深度剖析

转自：http://www.verycd.com/files/fb1b9ea09e63162183b1f40b40b87e5523150081

public class StringTest {

    public static void main(String[] args) {
        
        String s0 = new String("abc");//此语句产生几个String object
        
        String s1 = "abc";//此语句产生几个String object
        
        String s2 = new String("abc");//此语句产生几个String object
        
        String s3 = "abc";
        
        System.out.println(s0 == s1);//输出true or false
        System.out.println(s0 == s2);//输出true or false
        System.out.println(s1 == s2);//输出true or false
        System.out.println(s1 == s3);//输出true or false
        
        System.out.println(s1 == s0.intern());//输出true or false
        System.out.println(s1 == s1.intern());//输出true or false
        System.out.println(s1 == s2.intern());//输出true or false
        
        String hello = "hello";
        String hel = "hel";
        String lo = "lo";
        
        System.out.println(hello == "hel" + "lo");//输出true or false
        System.out.println(hello == "hel" + lo);//输出true or false
    }

}